Nuclear radiation diseases

Radiation sicknessnuclearwaste

The radiation poisoning (also called evil rays, acute radiation sickness, or more properly in clinical acute radiation syndrome) describes a set of potentially lethal symptoms related to exposure of tissues to a considerable part of the human body to a strong dose of ionizing radiation.

The poisoning is usually seen in a prodromal phase is not lethal in minutes or hours following irradiation. This stage lasts from several hours to several days and often manifests itself with symptoms such as diarrhea, nausea, vomiting, anorexia, rash. A period of latency, in which the subject appears in good condition. Finally comes the acute phase, which manifests as a symptom complex, usually with skin disorders, hematopoietic, gastrointestinal, respiratory and cerebro-vascular diseases.

The natural sources of radiation are generally not powerful enough to cause the syndrome, which is often caused by human activities, such as a nuclear accident, exposure to a radioactive source or an atomic explosion.

The alpha radiation has a low penetration power, so it is not dangerous to humans in cases of external irradiation. It becomes dangerous in situations where the radioactive source is inhaled or ingested - internal irradiation - in this case because it can directly affect radiosensitive tissues, typical case is the fact that radon is inhaled radioactive isotope and can decay inside of the human body emitting alpha radiation. The gamma radiation (consisting of high energy photons) instead of having a very high penetration power, can be dangerous for living beings in situations of external irradiation. The amount of radiation absorbed by a body is called the absorbed dose and is measured in gray, other sizes are important to consider the equivalent dose and the effective dose.

In the United States of America was prepared to fork "ALI" (Annual Limit on Intake) or "in the Annual Dose Limit" which is derived a limit to the amount of radioactive material absorbed by the body of an adult worker by inhalation or if swallowed in a year.

ALI is the smallest value allowable ingestion of a given radionuclide in a year, taken by the man of reference, which would cause damage equivalent to that of a single total irradiation dose of 5 rem (0.05 Sv) or a damage equivalent to radiation from a single organ with 50 rem (0.5 Sv), for any organ or tissue specific.

The dose-equivalent are currently specified in sievert (Sv), and a sievert equals 100 rem:

from 0.001 to 0.01 Sv (0.1 to 1 rem)

It is estimated that physiologically the body is exposed to 0.1 millirem in 24 hours (approximately 0.036 rem in a year): a part of this is unavoidable, because it is issued for example dall'isotopo natural radioactive potassium (K40), present within each human cell, irradiating the whole body from the inside every day.

Wanting to eliminate all of its potash, radioactive or not, this will result in death from congestive edema, hypertension and muscle weakness, in addition to heart failure.

The main radioactive element extraneous to the organism, which is located in the environment, especially in areas with some type of volcanism or seismic faults is radon gas. This gas, produced in the decay of radio, is heavier than air and may accumulate in parts of the valley slopes, especially in the basement and first floors are not well ventilated. There are devices on the market able to detect the radon gas.

Especially in areas with granite or basalt rocks which have undergone intense metamorphism in the earth, a contribution to the annual dose is provided by radioactive isotopes such as thorium, uranium and radium. This contribution varies from place to place and depends on the type of minerals in the surrounding soil or building materials (such as tuff).

Every hour of flying in an airliner, the usual quota of 10,000 m, subjects the body to radiation of cosmic rays range of value also varies according to solar storms and radiation values ranging from 0.1 to 1 millirem / h (maximum in the Concorde flying at 20,000 m), and therefore 10-hour intercontinental flight can give total doses greater than 1 millirem, and in 100 vol / year you can also score 0.300 rem / year or more.

The dose is fractionated, and therefore should not induce chromosome breakage and less stress by oxygen free radicals.

from 0.05 to 0.2 Sv (from 5 to 20 rem)

No symptoms. Some researchers argue that small doses of radiation may be beneficial. In the U.S. there is a federal limit of 50 mSv per year, which has been specified for workers exposed to radioactive substances and procedures. In the UK the annual limit for an employee classified as "operator with radiation" is 20 mSv. In Canada and Brazil, the maximum annual limit is 50 mSv (5,000 millirem), but the maximum dose that can be taken in 5 years is only 100 mSv. Usually the limits specified by the private companies are much closer, so as to avoid any accidental infringement of federal limits.

from 0.2 to 0.5 Sv (20 to 50 rem)

No apparent symptoms. The number of white blood cells decreases temporarily.

from 0.5 to 1 Sv (50 to 100 rem)

Mild radiation sickness with headache and a slightly increased risk of infection caused by alterations in the immune system. Possible temporary male infertility.

1 to 2 Sv (100 to 200 rem)

"The mild radiation poisoning", involves a 10% mortality after 30 days (LD 10/30). Typical symptoms include nausea, mild to moderate (with a 50% probability at 2 Sv), with occasional vomiting, which begins from 3 to 6 hours after irradiation and lasts for about a day. This episode is followed by a latent phase that lasts from 10 to 14 days, when symptoms are mild asthenia and malaise (a 50% chance to 2 Sv). The immune system undergoes depression, which causes an extended period of convalescence for many common infections and an increased risk of opportunistic infection. In men, it is common to the temporary sterility. The miscarriage or the increase incidence of premature delivery occurs commonly in pregnant women.

2 to 3 Sv (200 to 300 rem)

"The moderate radiation poisoning" means a mortality of 35% after 30 days (LD 35/30). Nausea is common continuous (in 100% of patients at 3 Sv), with a 50% risk of vomiting still 2 , 8 Sv The symptoms start from 1 to 6 hours after irradiation and last from 1 to 2 days. After this, there is a latent phase which lasts from 7 to 14 days, which ends with the appearance of the following symptoms: loss hair and fur all over his body (with 50% probability at 3 Sv), fatigue and general malaise. There is a massive loss of white blood cells, which greatly increases the risk of infection (similar to the most severe phase of AIDS ). There is the possibility of permanent sterility in females. convalescence, and for a possible eventual healing requires several months.

from 3 to 4 Sv (300 to 400 rem)

"The severe radiation poisoning", implies a 50% mortality after 30 days (LD 50/30). It has minor symptoms (such as loss of hair) similar to those of the dose of 2 to 3 Sievert, but these adding uncontrollable bleeding from the mouth, bleeding under the skin (petechiae) and bleeding kidney (with a 50% probability at 4 Sv), after a short lag phase. Anatoly Dyatlov received a dose of 390 rem during the Chernobyl disaster of 1986 . He died of heart failure in 1995, nine years after the accident. It is possible that the massive doses of radiation have affected his health.

4 to 6 Sv (from 400 to 600 rem)

"The acute radiation poisoning", involves a 60% mortality after 30 days (LD 60/30). Mortality passes from 60% to 4.5 Sv up to 90% at 6 Sv, unless the patient is apply intensive medical therapy, the intense symptoms begin about one hour to two hours after irradiation and last up to 2 days. After this, there is a latent phase that lasts from 7 to 14 days, after which symptoms appear similar to those of 3-4 Sv irradiation, with increased intensity. The final female infertility is very common at this point. Convalescence requires several months to a year. The leading cause of death, usually from 2 to 12 weeks after irradiation, are infections and internal bleeding.

Harry K. Daghlian, a nuclear physicist Armenian-American of 24 years, was irradiated with 510 rem (5.1 Sv) of radiation 21 August 1945, during an experiment of critical mass. Then working in the Los Alamos National Laboratory in New Mexico. The irradiation caused the death of the scientist after 28 days.

from 6 to 10 Sv (from 600 to 1,000 rem)

"The acute radiation poisoning", involves a 100% mortality after 14 days (LD 100/14). Survival depends on the medical ICU. The bone marrow is totally destroyed, so to ensure a fair chance of life is essential bone marrow transplantation. gastric and intestinal tissues are severely damaged. Symptoms begin 15 to 30 minutes after irradiation and last for up to 2 days, then you have a latent phase that lasts from 5 to 10 days after of that person dies of internal bleeding or infection in the few cases that recover, healing requires several years and will probably never be complete.

The farmer Devair Brazilian Alves Ferreira received a dose of approximately 7.0 Sv (700 rem) (Radiation from a source of gamma rays from cesium-137, abandoned in a landfill), during the Goiânia accident, but survived perhaps in part because the dose was fractionated.

10 to 50 Sv (from 1,000 to 5,000 rem)

"Acute poisoning radioactive", involves a 100% mortality after 7 days (LD 100/7). Exposure so high leads to the appearance of spontaneous symptoms in a time ranging from 5 to 30 min. After an fatigue and the occurrence of nausea immediate direct caused by activation of chemical receptors in the brain, caused by free radicals, abnormal metabolites and proteins generated by the irradiation, there is a period of some days in relative comfort, called latent phase or phase of the ghost who walks. After this week, it has a massive death of cells in the gastric and intestinal tissue, causing massive diarrhea, intestinal bleeding and loss of water, which leads to fluid and electrolyte imbalance. Death occurs after a few hours of delirium and coma because of poor circulation. In the vast majority of cases, death is inevitable, the only treatment that can be offered is that of pain management. Louis Slotin was exposed to about 21 Sv in a criticality accident May 21, 1946, and died nine days later, on May 30.

During the explosion of an atomic bomb becomes unlikely to survive by receiving a dose greater than 5000 rem (50 Sv): patients exposed to higher doses usually die within hours or days to the immediate effects of skin burns from radiation produced in ' field of infrared and visible light, or for bruises, fractures and internal and external bleeding and debris produced by the displacement of air caused by the explosion.

more than 50 Sv (> 5,000 rem)

An episode of the satellite program Myths (Discovery Channel) exhibited some species of insects to gamma rays (the source was the isotope cobalt-60) in a laboratory of Pacific Northwest National Laboratory. A 10,000 rad, about 70% of the cockroaches were dead before 30 days, and 30% survived. A 100,000 rad, all the cockroaches died instantly and 90% of the flour beetles were dead after 30 days, leaving only 10% of surviving insects.